Pfarrwaller



Marchi?, 1964- E. PFARRWALLER 3,125,125'

DoBBY Filed Feb. l, 1961 2 Sheets-Sheet 1 fwemar.'

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March 17, 1964 E. PFARRWALLER 3,125,125'

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United States Patent DBBY Erwin Pfarrwaller, Winterthur, Switzerland, msignor to Sulzer Freres, SA., Winterthur, Switzerland, a corporation of Switzerland Filed Feb. 1, 1961, Ser. No. 86,489 Claims priority, application Switzerland Feb. 12, 1960 7 Claims. (Cl. 139-71) The present invention relates to a dobby for selectively actuating the heddle frames of a weaving machine, the dobby including lifter rails which are simultaneously and in the same direction reciprocated by the main shaft of the weaving machine and which, by means of lifting blades, actuate rocking elements which effect the desired movements of the heddle frames.

An object of the invention is to provide a dobby for actuating the heddle frames of a weaving machine which dobby operates accurately, has a minimum number of parts and requires little space, particularly in the direction of movement of the lifter rails.

In the dobby according to the invention a single rocking lever actuated by cams on a drive shaft suflices to simultaneously, unidirectionally and reciprocatingly move the lifter rails in a dobby which rails are adapted to engage lifting blades pairwisely connected to rockable members. Each of the latter is connected to a heddle frame for reciprocatingly moving the heddle frame. The aforesaid mechanism which is interposed between the main drive shaft and the heddle frames includes lever transmissions whose lever arms are so dimensioned that the angular movements of the rockable members are the same whether the members are rocked by one rail or by the other rail.

The novel features which are considered characteristic of the invention are set forth with particularity in the appended claims, The invention itself, however, and additional objects and advantages thereof will best be understood from the following description of embodiments thereof when read in connection with the accompanying drawing wherein:

FIG. l is a diagrammatic longitudinal sectional side view of a dobby according to the invention.

FIG. 2 is a part sectional side view of a lever transmission forming part of the dobby shown in FIG. l.

FIGS. 3 and 4 are diagrammatic part sectional side views of modified lever transmissions.

Referring more particularly to FIG. l of the drawing, numeral 1l) designates a shaft which is driven at the same speed as the main shaft of a weaving machine, not shown, the heddle frames of which are actuated by the mechanism shown in FIG. 1. The shaft 1t) drives the main shaft 12 of the dobby by means of a chain 11 at one half the speed of the main shaft of the Weaving machine. Cams 13 are rigidly connected to the shaft 12 and Cooperate with follower rollers 14 mounted on a lever 15 which is rockable on a fulcrum 16 and has an arm 17. Lifter rails 21 and 22 are provided with pins 25 which extend into corresponding bores at one end of guide links 23 and 24, respectively. The other ends of the guide links are swingable on stationary fulcrums which are coaxial in the embodiment of the invention shown in FIG. 1. The guide links 23 and 24 are connected to the arm 17 of the lever 15 by means of links 18 and 19.

In order to assure a translatory movement of the lifter rails 21, 22 each rail is conected by a link 26 to a second guide link 27 whose length is equal to that of the first guide links 23 and 24. Only the link 26 and the guide link 27 for the rail 21 are shown in the drawing. The second guide link 27 for the rail 22 swings on the same fulcrum as the guide link 27 for the rails 21 and is not ICC shown in the drawing. Also not shown is the link 26 for the rail 22.

Lifting blades 31, 32 provided with lugs 33, 34, respectively, adapted to engage the channels of the rails 21 and 22, respectively, which have a U-shaped cross section, are pivotally connected at 51, 52 to a cam member 35 rockable on an axis 36. The member 35 engages follower rollers on a lever 37 swinging on a shaft 38 which is rigidly connected to the housing 28 of the dobby. The lever 37 is adjustably connected by means of a link 39 to an element 41 swinging on a stationary fulcrum 42. The element 41 is adjustably connected to a linkage 43 which is connected to a heddle frame, not shown, for actuating the latter. The adjustable connections between the elements 39 and 41 and 41 and 43 are for the purpose of altering the stroke of the heddle frame.

The lifting blades 31 and 32 are moved according to the position of holes in a pattern card 45. A needle 46 abutted by the end of a control rod 47 effects movement of the latter into the operating range of either a lower control rail 43 or an upper control rail 49, depending on whether or not the needle 46 meets a hole in the pattern card. The control rails 48 and 49 are substantially horizontally reciprocatingly moved in opposite directions by a conventional mechanism actuated by cams on the shaft 12. A suitable mechanism is disclosed in my copending application Serial No. 86,492 of same date as the present application. A control lever 50 movably connected to the control rod 47 is swung clockwise upon movement of the rod 47 to the right, or counterclockwise upon movement of the rod 47 to the left, as seen in FIG. l. The lifting blades 31 and 32 are operatively connected to the lever Sil and are moved by the latter so that either the lug 33 of the blade 31 engages the channel of the rail 21, or the lug 34 of the blade 32 engages the channel of the rail 22.

If the pins 51 and 52 which swingably connect the blades 31 and 32 to the cam member 35 are equidistant from the rocking axis 36, the strokes of the lugs 33 and 34 must be equal.

A link r19 is swingably connected to each end of the rail 22 by means of pins 25. The lower ends of the links 19 `are pivotally connected by pins 53 to the arms 17 of the levers 15, one of which is provided at each end of the rail 22. The stroke of the vertical movement of the rail 22 is equal to the extent of movement of the pins '53 at the ends of the arms 17.

The upper ends of links 118 are not directly connected to the lifter rail 21, because pins 54 on the lever 17 which pivotally support the lower enfds of the links 1S are only `about half as far away from the fulcrum 1-6 as the pins 53. lf the links 18 were directly connected to the rail 21 the stroke of the latter would amount to only about one half of the stroke of the lifter rail 22 so that the mechanism shown in IFIG. 1 would be inoperative.

To make the mechanism operative leverage changing means, henceforth called -lever transmissions, are provided. This is more cleanly shown in FIG. 2. The link 18 is connected to the guide link 23 by means of a pin 55. The relation between .the distance of the pin 55 from the fulcrurn of the link 23 and the distance of the pin 25 on the rail 21 from the fulcrum of the link 23 -is the same as the relation lbetween the distance of the pin y54- from the fulcrurn 16 and the distance of the pin 53 from the fulcrum 16. In this Way the strokes of the reciprocating movement of the rails 21 and 22 are made equal.

The arrangement shown in FIG. 2 combines the translatory effect of the guide links 23 and 24 on the lifter rails 3 21 and 22 with a leverage-changing effect without the provision of additional elements.

In the mechanism shown in FIGS.1 and 2 both links 23, 214 swing on the same fulcrum 56.

In the arrangement shown in FIG. 3 rectilinear guides 61 and `62 are provided for the lifter rails 2l and 22. A link 19 swingably connected to ya pin 53 at the end of a lever -arm 17 is also swingably connected to the lifter rail 22. A link `63?; is swingably connected .to the arm 17 by means of a pin 54 and is swingably connected to a pin 64 on a lever 165-. The latter swings on a fulcrum 66 and has an end 67 swinigably connected to a link 68 which is swingably connected to the Ilifter rail 21. In this |way a leverage 4is provided equalizing the stroke h1 of the rail 21 and the stroke h2 of the rail 22. The mechanism shown in FIG. `3, however, requires more operating elements than the mechanism shown in FIG. 2.

There are several ways of obtaining equal angular movement of the pins 51 and 52 on the cam member 35 which support the lifting blades 31 and 32, although only `one rocking lever is provided rfor both lifter rails. VFIG. 3 shows a mechanism including two different lever transmissions. The lever 65 increases the smaller stroke of the pin `64 to obtain the stroke h1. If the arm 17 is elongated to the right and a pin 69 is provided beyond the pin 53, the .greater stroke of the pin 69 must be reduced to the required stroke h2. Por this purpose a link 70 is pivotally connected to .the pin 69 and to the end 71 of a lever 72 swinging on the fulcrum 66 and a link 73 is provided which connects the lifter rail 22 to an intermediate point of lthe lever 72. The levers 65 or 72 may also serve as guide links for guiding the lifter rails 21 and 22 as do the guide links 23 and 24 in FIGS. l and 2.

Instead of providing -a lever transmission between the lever `15 and one of the lifter :rails it may be provided on the cam member 35, as shown in FIG. 4. In this mechanism la crank 75 which is rotated by means of a chain 76 by the main shaft of the fweaving machine, not shown, actuates a lever 77 rocking on a fulcrum 83. A lifter rail 78 is connected to an intermediate point of the lever 77 by means of a link `ill. A lifter rail 79 is connected to the end of the lever 77 by means of a link 82. Due to the different leverage of the connections of the links 81 and y82 to the lever 77 the stroke h3 of the rail 78 is smaller than the stroke h4 of the rail 82. The upper end positions 78a and 79a of the rails are shown lin dotted lines. The rails are individually `guided by guide links 84 and `8-5 Iwhich may have the same length or may have different lengths, as shown, and swing on coaxial fulcrums or on different fulcr-ums, as shown.

Lugs 86 and y87 of lifting blades '8S and 89 are selectively inserted in suitable channels of `the lifter rails 78 land 79. In order 'to obtain the desired lever transmission the pin `90 by means of which the lifting blade 88 is connected to the cam member 91 is so much closer to the ful'cmm 92 ofthe member 91 than the pin '93 connecting :the lifting blade 89 to the cam member 91 that the relation between the distance of the pin 90` from the `fulcrum 912 and of the pin `93 from the fulcrum 92 is the same as the relation between the distances of the fulcrums 94 and 495 from the fulcrum 83 of the lever 77. If this is so, the :angular movement of the member 91 is the same upon engagement of the lug 86 by the rail 78 and upon engagement of the lug `87 by the rail 79.

I claim:

l. in a dobby for actuating the heddle frames of a weaving machine:

a main drive shaft,

two reciprocatingly movable lifter rails,

rockable members,

means operatively connected to each of said rockable members for actuating a heddle frame,

a rocking lever operatively connected to said drive shaft to be rocked thereby,

separate means individually operatively connecting said lifter rails to said rocking lever at different distances from the fulcrum of said lever,

two lifting blades operatively connected to each of said rockable members, the lifting blades connected to the same rockable members being alternatingly engageable by said lifter rails for rocking said rockable members, and

leverage changing means formed in the operative connection between said rocking lever and said rockable members for equalizing the angles through which said rockable members are rocked by said lifter rails.

2. In a dobby as defined in claim 1 wherein said leverage changing means is formed by said means connecting said lifter rails to said rocking lever.

3. In a dobby as defined in claim 1 wherein said leverage changing means is formed by one of said means connecting said lifter rails to said rocking lever.

4. In a dobby as dened in claim l wherein said leverage changing means is formed in the operative connection of said lifting blades to the respective rockable member.

5. In a dobby for actuating the heddle frames of a weaving machine:

a main drive shaft,

two reciprocatingly movable lifter rails,

rockable members,

means operatively connected to each of said rockable members for actuating a heddle frame,

a rocking lever operativelyy connected to said drive shaft to be rocked thereby,

means operatively connecting said rocking lever to both said lifter rails for unidirectionally and simultaneously moving said lifter rails,

guide links swingable on stationary fulcrums and individually connected to said lifter rails for guiding the latter,

said means connecting said rocking lever to said lifter rails including a connecting link pivotally connected to one of said guide links and to said rocking lever, and

two lifting blades pivotally connected to each of said rockable members,

the lifting blades connected to the same rockable member being alternatingly engageable by said lifter rails for individually rocking said rockable members through equal angles by said lifter rails through the engaged lifting blades.

6. In a dobby for actuating the heddle frames of a weaving machine:

a main drive shaft;

two reciprocatingly movable lifter rails,

rockable members,

means operatively connected to each of said rockable members for actuating a heddle frame,

a rocking lever operatively connected to said drive shaft to be rocked thereby,

means operatively connecting said lifter rails to said rocking lever at different distances from the fulcrum of said lever, and

two lifting blades pivotally connected to each of said rockable members,

the lifting blades connected to the same rockable member being alternatingly engageable by said lifter rails for individually rocking said rockable members through equal angles by said lifter rails through the engaged lifting blades,

the distance of the pivot axes of said lifting blades connected to the same rockable member being different for equalizing the angular movements of said rockable member caused by said lifting blades.

7. In a dobby for actuating the heddle frames of a weaving machine:

a main drive shaft,

two reciprocatingly movable lifter rails,

rockable members,

means operatively connected to each of said rockable members for actuating a heddle frame,

a rocking lever operatively connected to said drive shaft to be rocked thereby,

means operatively connecting said rocking lever to both said lifter rails for unidirectionally and simultaneously moving said lifter rails,

two lifting blades pivotally connected to each of said rockable members,

the lifting blades connected to the same rockable mem` ber being alternatingly engageable by said lifter rails for individually rocking said rockable members through equal angles by said lifter rails through the engaged lifting blades,

said rocking lever having an arm extending substantially horizontally from one side of the rocking axis of the lever,

said connecting means being connected to said arm,

said rocking lever having a second arm extending from the rocking axis of the rocking lever in a direction substantially opposite to the direction of extension of said first arm,

said rocking lever having a third arm extending from the rocking axis of the rocking lever at an angle to said second arm,

cam means fast on said drive shaft, and

a cam follower roller mounted on the free end of said second and third arm and engaging said cam means.

References Citedin the file of this patent UNITED STATES PATENTS Germany Nov. 25, 1902 

1. IN A DOBBY FOR ACTUATING THE HEDDLE FRAMES OF A WEAVING MACHINE: A MAIN DRIVE SHAFT, TWO RECIPROCATINGLY MOVABLE LIFTER RAILS, ROCKABLE MEMBERS, MEANS OPERATIVELY CONNECTED TO EACH OF SAID ROCKABLE MEMBERS FOR ACTUATING A HEDDLE FRAME, A ROCKING LEVER OPERATIVELY CONNECTED TO SAID DRIVE SHAFT TO BE ROCKED THEREBY, SEPARATE MEANS INDIVIDUALLY OPERATIVELY CONNECTING SAID LIFTER RAILS TO SAID ROCKING LEVER AT DIFFERENT DISTANCES FROM THE FULCRUM OF SAID LEVER, 